The current proposal entails an investigation of some of the consequences of oxidative stress in yeast, with particular focus on aspects of mitochondrial dysfunction. The genetic approach central to this examination will allow for an unambiguous definition of cytochrome c peroxidase (CCP1) as part of the antioxidant defenses of the cell and the role it plays in conjunction with copper-zinc superoxide dismutase (SOD1). Specific Aim 1: Define the biological role of CCP1 The first specific aim of this study will address the issue of definitively characterizing the functional role of CCP1 as an antioxidant enzyme. Specific Aim 2: Evaluate the functional link between SOD1 and CCP1 The second specific aim of this study will investigate the potential existence and nature of a functional link between Ccplp and the ubiquitous antioxidant enzyme, Sodlp. [unreadable] [unreadable]